From GIS to the Desktop

Maps published in print or on the Web
must communicate visually, and the more visually rich their symbology,
color and graphic technique, the more successfully they will
communicate.

Adobe
Illustrator's graphic capabilities provide you many ways of enhancing
the visual quality of your GIS data, as shown in Figure 1, at left.

Software programs like Adobe Illustrator and Photoshop have evolved
into sophisticated communication tools, inviting cartographers to add
visual value to their maps using transparency, drop shadows, complex
graphic styles, and layered symbols, among other effects.

The visual quality of your maps, if not various aspects of your
workflow, may improve if you take your map from your GIS to the
desktop.In this first of several articles, we'll explore the value of
making that journey and review some travel tips to get you there.

Leaving Home
Starting a map in a GIS program and then switching to a desktop program
is a bother.Time, workflow management, and other factors could add up
to greater time and cost.But the benefits to going to the desktop can
outweigh the costs -- and those benefits may include workflow
efficiency or just simply producing a more visually valuable map as a
result.

Trip Planning
When planning your trip to the desktop, consider your "packing"
philosophy -- do you want to travel light or pack a lot of gear so you
have maximum flexibility at your fingertips? From your GIS, you can
take your map into Adobe Illustrator following either of two routes:

Export your compiled, color-coded
map as an Illustrator or editable PDF file (only graphic objects with
no GIS attribute data will be available to you in Illustrator), or

Save coverages as GIS-format files, such as ArcView Shapes
(GIS attribute data will be available when the files are imported into
Illustrator).

Choose the first route if you're
confident that the map you've compiled in your GIS has all of the
information it needs, at the final projection and perhaps close to the
final scale and with type labels generated.Choose the second if you
might have to integrate other information later in production or if you
feel a need to access or manipulate the data during map production.

Getting There is Half the Fun
Traveling either route, your data arrives in Illustrator as vector
points, lines or polygons.This means your data is "live," that is,
graphically editable, allowing you to select and edit constituent
points, shapes, color or symbology as often as you like until the
moment you complete the map and ship the file to a printer.Figure 2,
at right, shows that vector objects remain selectable and editable
throughout the production process.

To get your coverage files into Illustrator, use the MAPublisher suite
of GIS filters from Avenza Systems,
Inc. that can be installed as filters within Illustrator.With
MAPublisher's File > Import Map Data, you simply locate your
coverage files and import them.The data of each file is imported and
placed on a unique layer.(MAPublisher will split a coverage file into
separate layers for points, lines or polygons if your file contained a
mix of feature types.)

Figure 3.MAPublisher's Import
Map Data dialog.

Organizational Skills
Illustrator visually displays and prints using a hierarchical
structure.What's at the top of a stacking order displays or prints on
top of what's below.You'll want to organize your data, preferably
splitting it up into lots of layers, for two practical purposes.One
purpose is to visually organize the geographic structure of the map.
For example, you'll want the hydrography layers to underlay the
transportation layers.The second purpose is to help you later when you
need to select all of a class of geographic features.By splitting your
transportation features into separate layers for interstates, federal
highways, state highways, and so forth, you can globally select
interstates by targeting and selecting the interstates layer.Figure 4, at left, shows how
Illustrator's Layers palette lets you divide data into a hierarchical
structure; it also enables you to view, hide and lock groups of layers
for improved efficiency while you work.

If you colored your features in your GIS prior to exporting an
Illustrator or PDF file, then you can use Illustrator Select commands
to select features by their graphic color or line weight or other
graphic parameter.If you imported coverage files, then you can use
MAPublisher's Select by Attribute filter to select data by feature code
attributes.

The Layers palette allows you to group layers in families.You can
create a master Roads layer and have your data organized on sublayers
(one sublayer for interstates, another for federal highways, and so
forth).While working on hydrography, for example, you can hide the
Roads master layer and with it all the road linework, helping you
concentrate on the hydrography as you edit its data.

A special breed of layer is called a "template." This is a non-printing
layer that can be used as a visual reference or to store data that
you're not entirely comfortable with discarding until the map is closer
to completion.

The end result is that you've organized the map hierarchically in
layers, and given yourself the flexibility of working with geographic
features on individual layers.

Symbolizing Things
Now that your map is organized, you're ready to benefit from
Illustrator's powerhouse of graphic symbology and visual effects.

Your principal tools are Illustrator's palettes.With palettes, like
the Color and Stroke palettes, you directly "paint" your lines and
polygons.With others, like the Styles and Symbols palettes, you create
master styles or graphic symbols that permit you to make changes to the
master that Illustrator then automatically conveys to all data painted
with those styles or symbols.The Appearance palette is a powerful
laboratory for creating complex symbols and visual effects.

Figure 5a

Figure 5d

Figure 5b

Figure 5e

Figure 5c

Figures 5a, 5b, 5c, 5d, 5e (above and to the left), show Illustrator's
principal palettes for editing the graphics of your data.

Let's look at some easy
symbolization techniques you can perform.(In a future article, we'll
delve in detail into the steps you would take to achieve these
techniques.)

Color Swatches
Create a color library for your map using the Eyedropper tool to sample
colors from photographs, scans, other maps, or from a terrain image.
Each color swatch can be fine-tuned to precise CMYK or Pantone values
for printing or to RGB values for Web images.A swatch can be made
"global" so that later adjustments to the color composition of the
swatch will be reflected automatically in all features originally
painted with that swatch.The swatches palette (shown at
left in Figure 6) serves as a document-wide color, gradient and pattern
library.The swatches of other documents can also be accessed, lending
a uniformity of color among similar maps.)

Multi-line Line Symbols
Create a multi-line interstate symbol by constructing the symbol
hierarchically in the Appearance palette.Create a thick green line
("stroke"), overlay it with a thinner white stroke and overlay that
with a thinner green line.Then turn this symbol into a Graphic Style
so that when you select all data on your interstates layer, you can
paint all lines with this symbol with a single mouse click in the
Styles palette.Or, get more creative and construct an interstate style
that's transparent in the middle instead of white, letting other
symbology or even a background terrain image appear between the
parallel lines of the interstates.

Figure 7a shows the Appearance pallette for
creating an interstate symbol with a transparent middle, and Figure 7b
shows the resulting interstate symbol.For a more conventional
interstate symbol, see the Appearance palette in Figure 5e.

Stroked Type
Sometimes type cannot visually compete against a background of other
symbology or a terrain image.A classic technique that you can quickly
replicate is adding a white border around the letter characters.The
Appearance palette lets you add a white stroke below the characters (so
that the white outline doesn't cut into, and thus deform, the letter
characters).Again, you can turn this into a Style and apply it to all
selected type with a single mouse click.

Double-bordered Polygons
Select a park, administrative area or other polygon.In the Appearance
palette, give the polygon line a thick dark stroke.Then add a second
lighter, thinner stroke and apply the Illustrator's Offset Path effect
to wrap the second stroke as an parallel line inside the first line.If
you need to adjust the shape of this polygon, both boundary lines flow
perfectly in sync following your edit to the polygon.

Figures 9a and 9b
shows using the Offset Path effect to create a double-bordered polygon.

Vignettes
Select a large water polygon and give it a light vignette that follows
the shoreline using the Inner Glow effect.If you need to edit the
shape of the shoreline, the vignette adjusts automatically.Also, you
can recolor the vignette by selecting the polygon and editing the
parameters of the Inner Glow effect.

Figure 10 shows the
result of using the Inner Glow effect to create a shoreline vignette.

Gradients
To focus attention on a feature, create a radial gradient underneath
it, or use a linear gradient to as a tab leader connecting an inset to
its location on the main map.Gradients are "live," meaning that
changes to the shape of the object that holds the gradient results in
an automatic update of the gradient within the object.Edits to the
gradient's colors are also automatically reflected in the object.

Figure 11 shows an example of a radial
gradient and a linear gradient.

Gradient Mesh
Does your map have large areas of plain color, like a large park or
administrative area? Break the monotony by turning a polygon into an
Illustrator gradient mesh.The mesh allows you to select mesh points
and assign them different colors or tints.The result is a polygon that
appears airbrushed with undulating colors.

Figure 12 shows
filling a polygon with a gradient mesh.

Drop Shadows
Visually heighten the prominence of point symbols (including highway
shields) with high-resolution drop shadows that cast soft shadows on
symbology below them.The symbol shapes and their drop shadows remain
"live," allowing you to change color, shape, shadow opacity as you
develop the map and see the interplay between symbols and other map
features.

Figure 13 shows how drop shadows can fall on other symbols, type and
background images.

Illustrator SymbolsIf you use graphic symbols to
represent your point data, Illustrator offers you a flexible way to
maintain and change symbol designs.For a recreation map, for example,
create or add a master symbol to Illustrator's Symbols palette.Drag
and drop symbols from the palette at the locations of your point data.
Later, you may decide that the size, color, shape or overall design of
the symbol can be improved.You edit the master symbol and all
"instances" of the master symbol are changed automatically across the
map.Figure 14, to the left, shows
Illustrator's Symbols palette, a library of symbols that can also be
accessed from other documents.

3D Symbols
Turn a mundane flat map symbol like a camping tent or picnic table into
an eye-catching 3D symbol.Using Illustrator's 3D Effect, you can
revolve, bevel and extrude any graphic shape.Like all of Illustrator's
Effects, the 3D effect is "live." You can edit it later, adjusting its
3D properties.Creating a Graphic Style from it, you can easily turn
other flat symbols into 3D symbols with a single mouse click-all will
share the same rotation, extrusion and bevel properties.Figure 15, at right, shows Illustrator's
3D Effect applied to three symbols.The red centerlines highlight the
original shapes you draw that serve as input for the 3D Effect.

Transparency
Select your polygons for various classes of federal lands, assign each
class a distinctive fill color, and then adjust their transparency
level and blending mode so that they colorize a terrain image sitting
in the background.This is a quick way to make a design mock-up without
having to tediously transfer vector artwork from Illustrator to
Photoshop to accomplish the same effect.

Figure 16 shows a
background terrain image colorized by the polygon for a city boundary
that has been filled with color and given transparency and blending
mode parameters.

Masking
Some of your polygons may never see the light of day as symbolized
vector objects.Instead, you may choose to import them into Photoshop
from Illustrator so that you can use them to select and mask areas of a
raster image, such as a terrain image.(Illustrator lets you register a
raster image from Photoshop so that Illustrator artwork can be brought
into Photoshop exactly in position relative to the raster image.) In
Photoshop, you use masks to screen areas, colorize area features, or
create special visual effects like drop shadows and vignettes.

Take a Free Trip!
Desktop software makes this kind of flexibility easy and efficient to
achieve.Download
a tryout version of Adobe Illustrator.You can also download a demo
version of the Avenza MAPublisher filters.

You can read
excerpts from the Adobe Illustrator CS Wow! Book (Peachpit Press) that
relate to cartography and type treatments using Illustrator's tools and
techniques.

What the Future Holds
Our next article will focus on importing your GIS map or coverage files
into Illustrator and how you would work with the data in Illustrator to
edit your data and organize your map graphically and geographically.